linux/drivers/input/touchscreen/da9034-ts.c
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   1/*
   2 * Touchscreen driver for Dialog Semiconductor DA9034
   3 *
   4 * Copyright (C) 2006-2008 Marvell International Ltd.
   5 *      Fengwei Yin <fengwei.yin@marvell.com>
   6 *      Bin Yang  <bin.yang@marvell.com>
   7 *      Eric Miao <eric.miao@marvell.com>
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License version 2 as
  11 * published by the Free Software Foundation.
  12 */
  13
  14#include <linux/module.h>
  15#include <linux/kernel.h>
  16#include <linux/init.h>
  17#include <linux/delay.h>
  18#include <linux/platform_device.h>
  19#include <linux/input.h>
  20#include <linux/workqueue.h>
  21#include <linux/mfd/da903x.h>
  22#include <linux/slab.h>
  23
  24#define DA9034_MANUAL_CTRL      0x50
  25#define DA9034_LDO_ADC_EN       (1 << 4)
  26
  27#define DA9034_AUTO_CTRL1       0x51
  28
  29#define DA9034_AUTO_CTRL2       0x52
  30#define DA9034_AUTO_TSI_EN      (1 << 3)
  31#define DA9034_PEN_DETECT       (1 << 4)
  32
  33#define DA9034_TSI_CTRL1        0x53
  34#define DA9034_TSI_CTRL2        0x54
  35#define DA9034_TSI_X_MSB        0x6c
  36#define DA9034_TSI_Y_MSB        0x6d
  37#define DA9034_TSI_XY_LSB       0x6e
  38
  39enum {
  40        STATE_IDLE,     /* wait for pendown */
  41        STATE_BUSY,     /* TSI busy sampling */
  42        STATE_STOP,     /* sample available */
  43        STATE_WAIT,     /* Wait to start next sample */
  44};
  45
  46enum {
  47        EVENT_PEN_DOWN,
  48        EVENT_PEN_UP,
  49        EVENT_TSI_READY,
  50        EVENT_TIMEDOUT,
  51};
  52
  53struct da9034_touch {
  54        struct device           *da9034_dev;
  55        struct input_dev        *input_dev;
  56
  57        struct delayed_work     tsi_work;
  58        struct notifier_block   notifier;
  59
  60        int     state;
  61
  62        int     interval_ms;
  63        int     x_inverted;
  64        int     y_inverted;
  65
  66        int     last_x;
  67        int     last_y;
  68};
  69
  70static inline int is_pen_down(struct da9034_touch *touch)
  71{
  72        return da903x_query_status(touch->da9034_dev, DA9034_STATUS_PEN_DOWN);
  73}
  74
  75static inline int detect_pen_down(struct da9034_touch *touch, int on)
  76{
  77        if (on)
  78                return da903x_set_bits(touch->da9034_dev,
  79                                DA9034_AUTO_CTRL2, DA9034_PEN_DETECT);
  80        else
  81                return da903x_clr_bits(touch->da9034_dev,
  82                                DA9034_AUTO_CTRL2, DA9034_PEN_DETECT);
  83}
  84
  85static int read_tsi(struct da9034_touch *touch)
  86{
  87        uint8_t _x, _y, _v;
  88        int ret;
  89
  90        ret = da903x_read(touch->da9034_dev, DA9034_TSI_X_MSB, &_x);
  91        if (ret)
  92                return ret;
  93
  94        ret = da903x_read(touch->da9034_dev, DA9034_TSI_Y_MSB, &_y);
  95        if (ret)
  96                return ret;
  97
  98        ret = da903x_read(touch->da9034_dev, DA9034_TSI_XY_LSB, &_v);
  99        if (ret)
 100                return ret;
 101
 102        touch->last_x = ((_x << 2) & 0x3fc) | (_v & 0x3);
 103        touch->last_y = ((_y << 2) & 0x3fc) | ((_v & 0xc) >> 2);
 104
 105        return 0;
 106}
 107
 108static inline int start_tsi(struct da9034_touch *touch)
 109{
 110        return da903x_set_bits(touch->da9034_dev,
 111                        DA9034_AUTO_CTRL2, DA9034_AUTO_TSI_EN);
 112}
 113
 114static inline int stop_tsi(struct da9034_touch *touch)
 115{
 116        return da903x_clr_bits(touch->da9034_dev,
 117                        DA9034_AUTO_CTRL2, DA9034_AUTO_TSI_EN);
 118}
 119
 120static inline void report_pen_down(struct da9034_touch *touch)
 121{
 122        int x = touch->last_x;
 123        int y = touch->last_y;
 124
 125        x &= 0xfff;
 126        if (touch->x_inverted)
 127                x = 1024 - x;
 128        y &= 0xfff;
 129        if (touch->y_inverted)
 130                y = 1024 - y;
 131
 132        input_report_abs(touch->input_dev, ABS_X, x);
 133        input_report_abs(touch->input_dev, ABS_Y, y);
 134        input_report_key(touch->input_dev, BTN_TOUCH, 1);
 135
 136        input_sync(touch->input_dev);
 137}
 138
 139static inline void report_pen_up(struct da9034_touch *touch)
 140{
 141        input_report_key(touch->input_dev, BTN_TOUCH, 0);
 142        input_sync(touch->input_dev);
 143}
 144
 145static void da9034_event_handler(struct da9034_touch *touch, int event)
 146{
 147        int err;
 148
 149        switch (touch->state) {
 150        case STATE_IDLE:
 151                if (event != EVENT_PEN_DOWN)
 152                        break;
 153
 154                /* Enable auto measurement of the TSI, this will
 155                 * automatically disable pen down detection
 156                 */
 157                err = start_tsi(touch);
 158                if (err)
 159                        goto err_reset;
 160
 161                touch->state = STATE_BUSY;
 162                break;
 163
 164        case STATE_BUSY:
 165                if (event != EVENT_TSI_READY)
 166                        break;
 167
 168                err = read_tsi(touch);
 169                if (err)
 170                        goto err_reset;
 171
 172                /* Disable auto measurement of the TSI, so that
 173                 * pen down status will be available
 174                 */
 175                err = stop_tsi(touch);
 176                if (err)
 177                        goto err_reset;
 178
 179                touch->state = STATE_STOP;
 180
 181                /* FIXME: PEN_{UP/DOWN} events are expected to be
 182                 * available by stopping TSI, but this is found not
 183                 * always true, delay and simulate such an event
 184                 * here is more reliable
 185                 */
 186                mdelay(1);
 187                da9034_event_handler(touch,
 188                                     is_pen_down(touch) ? EVENT_PEN_DOWN :
 189                                                          EVENT_PEN_UP);
 190                break;
 191
 192        case STATE_STOP:
 193                if (event == EVENT_PEN_DOWN) {
 194                        report_pen_down(touch);
 195                        schedule_delayed_work(&touch->tsi_work,
 196                                msecs_to_jiffies(touch->interval_ms));
 197                        touch->state = STATE_WAIT;
 198                }
 199
 200                if (event == EVENT_PEN_UP) {
 201                        report_pen_up(touch);
 202                        touch->state = STATE_IDLE;
 203                }
 204                break;
 205
 206        case STATE_WAIT:
 207                if (event != EVENT_TIMEDOUT)
 208                        break;
 209
 210                if (is_pen_down(touch)) {
 211                        start_tsi(touch);
 212                        touch->state = STATE_BUSY;
 213                } else {
 214                        report_pen_up(touch);
 215                        touch->state = STATE_IDLE;
 216                }
 217                break;
 218        }
 219        return;
 220
 221err_reset:
 222        touch->state = STATE_IDLE;
 223        stop_tsi(touch);
 224        detect_pen_down(touch, 1);
 225}
 226
 227static void da9034_tsi_work(struct work_struct *work)
 228{
 229        struct da9034_touch *touch =
 230                container_of(work, struct da9034_touch, tsi_work.work);
 231
 232        da9034_event_handler(touch, EVENT_TIMEDOUT);
 233}
 234
 235static int da9034_touch_notifier(struct notifier_block *nb,
 236                                 unsigned long event, void *data)
 237{
 238        struct da9034_touch *touch =
 239                container_of(nb, struct da9034_touch, notifier);
 240
 241        if (event & DA9034_EVENT_TSI_READY)
 242                da9034_event_handler(touch, EVENT_TSI_READY);
 243
 244        if ((event & DA9034_EVENT_PEN_DOWN) && touch->state == STATE_IDLE)
 245                da9034_event_handler(touch, EVENT_PEN_DOWN);
 246
 247        return 0;
 248}
 249
 250static int da9034_touch_open(struct input_dev *dev)
 251{
 252        struct da9034_touch *touch = input_get_drvdata(dev);
 253        int ret;
 254
 255        ret = da903x_register_notifier(touch->da9034_dev, &touch->notifier,
 256                        DA9034_EVENT_PEN_DOWN | DA9034_EVENT_TSI_READY);
 257        if (ret)
 258                return -EBUSY;
 259
 260        /* Enable ADC LDO */
 261        ret = da903x_set_bits(touch->da9034_dev,
 262                        DA9034_MANUAL_CTRL, DA9034_LDO_ADC_EN);
 263        if (ret)
 264                return ret;
 265
 266        /* TSI_DELAY: 3 slots, TSI_SKIP: 3 slots */
 267        ret = da903x_write(touch->da9034_dev, DA9034_TSI_CTRL1, 0x1b);
 268        if (ret)
 269                return ret;
 270
 271        ret = da903x_write(touch->da9034_dev, DA9034_TSI_CTRL2, 0x00);
 272        if (ret)
 273                return ret;
 274
 275        touch->state = STATE_IDLE;
 276        detect_pen_down(touch, 1);
 277
 278        return 0;
 279}
 280
 281static void da9034_touch_close(struct input_dev *dev)
 282{
 283        struct da9034_touch *touch = input_get_drvdata(dev);
 284
 285        da903x_unregister_notifier(touch->da9034_dev, &touch->notifier,
 286                        DA9034_EVENT_PEN_DOWN | DA9034_EVENT_TSI_READY);
 287
 288        cancel_delayed_work_sync(&touch->tsi_work);
 289
 290        touch->state = STATE_IDLE;
 291        stop_tsi(touch);
 292        detect_pen_down(touch, 0);
 293
 294        /* Disable ADC LDO */
 295        da903x_clr_bits(touch->da9034_dev,
 296                        DA9034_MANUAL_CTRL, DA9034_LDO_ADC_EN);
 297}
 298
 299
 300static int da9034_touch_probe(struct platform_device *pdev)
 301{
 302        struct da9034_touch_pdata *pdata = pdev->dev.platform_data;
 303        struct da9034_touch *touch;
 304        struct input_dev *input_dev;
 305        int ret;
 306
 307        touch = kzalloc(sizeof(struct da9034_touch), GFP_KERNEL);
 308        if (touch == NULL) {
 309                dev_err(&pdev->dev, "failed to allocate driver data\n");
 310                return -ENOMEM;
 311        }
 312
 313        touch->da9034_dev = pdev->dev.parent;
 314
 315        if (pdata) {
 316                touch->interval_ms      = pdata->interval_ms;
 317                touch->x_inverted       = pdata->x_inverted;
 318                touch->y_inverted       = pdata->y_inverted;
 319        } else
 320                /* fallback into default */
 321                touch->interval_ms      = 10;
 322
 323        INIT_DELAYED_WORK(&touch->tsi_work, da9034_tsi_work);
 324        touch->notifier.notifier_call = da9034_touch_notifier;
 325
 326        input_dev = input_allocate_device();
 327        if (!input_dev) {
 328                dev_err(&pdev->dev, "failed to allocate input device\n");
 329                ret = -ENOMEM;
 330                goto err_free_touch;
 331        }
 332
 333        input_dev->name         = pdev->name;
 334        input_dev->open         = da9034_touch_open;
 335        input_dev->close        = da9034_touch_close;
 336        input_dev->dev.parent   = &pdev->dev;
 337
 338        __set_bit(EV_ABS, input_dev->evbit);
 339        __set_bit(ABS_X, input_dev->absbit);
 340        __set_bit(ABS_Y, input_dev->absbit);
 341        input_set_abs_params(input_dev, ABS_X, 0, 1023, 0, 0);
 342        input_set_abs_params(input_dev, ABS_Y, 0, 1023, 0, 0);
 343
 344        __set_bit(EV_KEY, input_dev->evbit);
 345        __set_bit(BTN_TOUCH, input_dev->keybit);
 346
 347        touch->input_dev = input_dev;
 348        input_set_drvdata(input_dev, touch);
 349
 350        ret = input_register_device(input_dev);
 351        if (ret)
 352                goto err_free_input;
 353
 354        platform_set_drvdata(pdev, touch);
 355        return 0;
 356
 357err_free_input:
 358        input_free_device(input_dev);
 359err_free_touch:
 360        kfree(touch);
 361        return ret;
 362}
 363
 364static int da9034_touch_remove(struct platform_device *pdev)
 365{
 366        struct da9034_touch *touch = platform_get_drvdata(pdev);
 367
 368        input_unregister_device(touch->input_dev);
 369        kfree(touch);
 370
 371        return 0;
 372}
 373
 374static struct platform_driver da9034_touch_driver = {
 375        .driver = {
 376                .name   = "da9034-touch",
 377                .owner  = THIS_MODULE,
 378        },
 379        .probe          = da9034_touch_probe,
 380        .remove         = da9034_touch_remove,
 381};
 382module_platform_driver(da9034_touch_driver);
 383
 384MODULE_DESCRIPTION("Touchscreen driver for Dialog Semiconductor DA9034");
 385MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>, Bin Yang <bin.yang@marvell.com>");
 386MODULE_LICENSE("GPL");
 387MODULE_ALIAS("platform:da9034-touch");
 388